The present invention relates to a pole anchoring system for supporting hollow poles, such as electrical distribution poles, vertically over a hard support surface, such as rock, concrete or the like.
It is known to anchor solid wooden poles vertically over a hard surface such as rock, concrete or the like by securing a harness about the lower portion of the pole and providing anchoring bolts which extend into the ground and secured to the harness whereby to hold the pole vertically over the hard surface. Such systems are described in my earlier U.S. Pat. Nos. 4,218,858 and 5,133,164. These anchoring devices have been primarily used for anchoring small diameter wooden poles such as telephone poles. However, with very large diameter hollow poles reaching heights of 50 feet or more, and top loaded with electrical wires, the anchoring system would be subjected to a lot of stress due to pole deflection loads often in the range of 5 to 20 degrees. Because of such stresses transmitted to the anchoring system, it has not been feasible to adapt these anchoring systems for supporting hollow metal distribution poles as such deflection in the poles would cause the hollow pole to buckle locally or to experience local buckling at its attachments with the harness assembly and the load would eventually cause the entire pole and possibly adjacent poles to bend or break and fall or be suspended by the electrical wires connected to adjacent poles.
A further disadvantage of adapting such anchoring system to hollow metal distribution poles is that these poles are usually constructed as hollow cylindrical poles and the thickness of the side wall of the pole is very thin, usually in the range of {fraction (1/16)} inch to about xc2xc inch maximum. Adapting a harness assembly about such poles would require drilling into the harness and into the pole and inserting large tapping bolts to make a connection between the harness and the pole. Because these poles are subjected to vibration during high wind loads, the constant vibration or movement in the pole could cause these fasteners to wear and eventually release.
A still further disadvantage of using hollow metal poles is that the load bearing surface at the bottom of the pole is extremely small and is constituted by the surface contact area of the circumferential wall of the pole which is usually less than 10 percent of the diameter of the pole at its bottom end.
It is a feature of the present invention to provide a pole anchoring system for supporting a hollow distribution pole and which substantially overcomes the above-mentioned disadvantages.
Another feature of the present invention is to provide a pole anchoring system and wherein a solid plug is disposed in close fit in a lower section of the distribution pole to increase its rigidity at its bottom end section, and to increase its load bearing surface as well as permitting a rigid connection with a harness and bolt anchoring system.
According to the above features, from a broad aspect, the present invention provides a pole anchoring system for supporting a hollow pole vertically over a hard support surface, such as rock, concrete or the like. The anchoring system comprises a solid plug of predetermined length and diameter and adapted for close fit in a lower section of the hollow distribution pole. A harness assembly is connected about the lower section of the hollow distribution pole by connecting means. The harness assembly has at least three anchor bolt restraining guide means vertically spaced apart about the harness assembly for captively receiving an upper portion of an associated anchor bolt of an anchor bolt assembly in each of the restraining guide means. The anchor bolt assembly has a lower bolt anchoring section and an upper bolt anchor actuation means.